The terrain looks so beautiful, I cannot wait to experience it myself! So you are pretty much done with the terrain upgrades? That is what I understood from the first paragraph of the update you posted. If so, and out of my own curiosity, what else are you wanting/planning to work on before the release of 0.990?

So after release of beta, modders should find or create PBR textures for their planets addons. This is mandatory now: soil textures must have albedo, displacement and roughness maps, ambient occlusion and metallness map will be added also. And in the release they probably will be in a compressed DDS format, which also will be a mandatory.